Removal of particles from wafer stage using wafer-formed cleaning material (cleaning wafer)

As a method of removing particles from a wafer stage. The use of a wafer-shaped cleaning material (hereafter, Cleaning Wafer) was considered for removal of the particles. One concern in using a Cleaning Wafer was that it might be caught in the wafer transfer system; such a failure can be prevented by adjusting the viscoelasticity parameters of the cleaning layer. The other concern was that the Cleaning Wafer might contaminate the wafer stage. The viscoelasticity cleaning layer is designed to produce less contamination. Consequently, by using a Cleaning Wafer, the amount of labor required for wafer cleaning can be decreased significantly.